Remove the additional data copy when handing a received MAD up to userspace.
Only a single data copy to the user's buffer is now performed. Checks for
the correct userspace buffer size are also tightened.
Signed-off-by: Sean Hefty <[EMAIL PROTECTED]>
---
NOTE: I tested this on a node running opensm, but I have no way of testing that
received RMPP MADs are copied correctly.
Index: user_mad.c
===================================================================
--- user_mad.c (revision 5532)
+++ user_mad.c (working copy)
@@ -121,9 +121,9 @@ struct ib_umad_file {
struct ib_umad_packet {
struct ib_mad_send_buf *msg;
+ struct ib_mad_recv_wc *recv_wc;
struct list_head list;
int length;
- struct list_head seg_list;
struct ib_user_mad mad;
};
@@ -188,62 +188,6 @@ static int data_offset(u8 mgmt_class)
return IB_MGMT_RMPP_HDR;
}
-static int copy_recv_mad(struct ib_mad_recv_wc *mad_recv_wc,
- struct ib_umad_packet *packet)
-{
- struct ib_mad_recv_buf *seg_buf;
- struct ib_rmpp_mad *rmpp_mad;
- void *data;
- struct ib_rmpp_segment *seg;
- int size, len, offset;
- u8 flags;
-
- len = mad_recv_wc->mad_len;
- if (len <= sizeof(struct ib_mad)) {
- memcpy(&packet->mad.data, mad_recv_wc->recv_buf.mad, len);
- return 0;
- }
-
- /* Multipacket (RMPP) MAD */
- offset = data_offset(mad_recv_wc->recv_buf.mad->mad_hdr.mgmt_class);
-
- list_for_each_entry(seg_buf, &mad_recv_wc->rmpp_list, list) {
- rmpp_mad = (struct ib_rmpp_mad *) seg_buf->mad;
- flags = ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr);
-
- if (flags & IB_MGMT_RMPP_FLAG_FIRST) {
- size = sizeof(*rmpp_mad);
- memcpy(&packet->mad.data, rmpp_mad, size);
- } else {
- data = (void *) rmpp_mad + offset;
- if (flags & IB_MGMT_RMPP_FLAG_LAST)
- size = len;
- else
- size = sizeof(*rmpp_mad) - offset;
- seg = kmalloc(sizeof(struct ib_rmpp_segment) +
- sizeof(struct ib_rmpp_mad) - offset,
- GFP_KERNEL);
- if (!seg)
- return -ENOMEM;
- memcpy(seg->data, data, size);
- list_add_tail(&seg->list, &packet->seg_list);
- }
- len -= size;
- }
- return 0;
-}
-
-static void free_packet(struct ib_umad_packet *packet)
-{
- struct ib_rmpp_segment *seg, *tmp;
-
- list_for_each_entry_safe(seg, tmp, &packet->seg_list, list) {
- list_del(&seg->list);
- kfree(seg);
- }
- kfree(packet);
-}
-
static void send_handler(struct ib_mad_agent *agent,
struct ib_mad_send_wc *send_wc)
{
@@ -267,25 +211,20 @@ static void recv_handler(struct ib_mad_a
{
struct ib_umad_file *file = agent->context;
struct ib_umad_packet *packet;
- int length;
if (mad_recv_wc->wc->status != IB_WC_SUCCESS)
- goto out;
+ goto err1;
- length = mad_recv_wc->mad_len;
- packet = kzalloc(sizeof *packet + sizeof(struct ib_mad), GFP_KERNEL);
+ packet = kzalloc(sizeof *packet, GFP_KERNEL);
if (!packet)
- goto out;
- INIT_LIST_HEAD(&packet->seg_list);
- packet->length = length;
+ goto err1;
- if (copy_recv_mad(mad_recv_wc, packet)) {
- free_packet(packet);
- goto out;
- }
+ packet->length = mad_recv_wc->mad_len;
+ packet->recv_wc = mad_recv_wc;
packet->mad.hdr.status = 0;
- packet->mad.hdr.length = length + sizeof (struct ib_user_mad);
+ packet->mad.hdr.length = sizeof (struct ib_user_mad) +
+ mad_recv_wc->mad_len;
packet->mad.hdr.qpn = cpu_to_be32(mad_recv_wc->wc->src_qp);
packet->mad.hdr.lid = cpu_to_be16(mad_recv_wc->wc->slid);
packet->mad.hdr.sl = mad_recv_wc->wc->sl;
@@ -301,21 +240,87 @@ static void recv_handler(struct ib_mad_a
}
if (queue_packet(file, agent, packet))
- free_packet(packet);
+ goto err2;
+ return;
-out:
+err2:
+ kfree(packet);
+err1:
ib_free_recv_mad(mad_recv_wc);
}
+static ssize_t copy_recv_mad(char __user *buf, struct ib_umad_packet *packet,
+ size_t count)
+{
+ struct ib_mad_recv_buf *recv_buf;
+ int left, seg_payload, offset, max_seg_payload;
+
+ /* We need enough room to copy the first (or only) MAD segment. */
+ recv_buf = &packet->recv_wc->recv_buf;
+ if ((packet->length <= sizeof (*recv_buf->mad) &&
+ count < sizeof (packet->mad) + packet->length) ||
+ (packet->length > sizeof (*recv_buf->mad) &&
+ count < sizeof (packet->mad) + sizeof (*recv_buf->mad)))
+ return -EINVAL;
+
+ if (copy_to_user(buf, &packet->mad, sizeof (packet->mad)))
+ return -EFAULT;
+
+ buf += sizeof (packet->mad);
+ seg_payload = min_t(int, packet->length, sizeof (*recv_buf->mad));
+ if (copy_to_user(buf, recv_buf->mad, seg_payload))
+ return -EFAULT;
+
+ if (seg_payload < packet->length) {
+ /*
+ * Multipacket RMPP MAD message. Copy remainder of message.
+ * Note that last segment may have a shorter payload.
+ */
+ if (count < sizeof (packet->mad) + packet->length) {
+ /*
+ * The buffer is too small, return the first RMPP
segment,
+ * which includes the RMPP message length.
+ */
+ return -ENOSPC;
+ }
+ offset = data_offset(recv_buf->mad->mad_hdr.mgmt_class);
+ max_seg_payload = sizeof (struct ib_mad) - offset;
+
+ for (left = packet->length - seg_payload, buf += seg_payload;
+ left; left -= seg_payload, buf += seg_payload) {
+ recv_buf = container_of(recv_buf->list.next,
+ struct ib_mad_recv_buf, list);
+ seg_payload = min(left, max_seg_payload);
+ if (copy_to_user(buf, ((void *) recv_buf->mad) + offset,
+ seg_payload))
+ return -EFAULT;
+ }
+ }
+ return sizeof (packet->mad) + packet->length;
+}
+
+static ssize_t copy_send_mad(char __user *buf, struct ib_umad_packet *packet,
+ size_t count)
+{
+ ssize_t size = sizeof (packet->mad) + packet->length;
+
+ if (count < size)
+ return -EINVAL;
+
+ if (copy_to_user(buf, &packet->mad, size))
+ return -EFAULT;
+
+ return size;
+}
+
static ssize_t ib_umad_read(struct file *filp, char __user *buf,
size_t count, loff_t *pos)
{
struct ib_umad_file *file = filp->private_data;
- struct ib_rmpp_segment *seg;
struct ib_umad_packet *packet;
- ssize_t ret, size;
+ ssize_t ret;
- if (count < sizeof (struct ib_user_mad) + sizeof (struct ib_mad))
+ if (count < sizeof (struct ib_user_mad))
return -EINVAL;
spin_lock_irq(&file->recv_lock);
@@ -338,52 +343,21 @@ static ssize_t ib_umad_read(struct file
spin_unlock_irq(&file->recv_lock);
- size = min_t(int, sizeof (struct ib_mad), packet->length);
- if (copy_to_user(buf, &packet->mad,
- sizeof(struct ib_user_mad) + size)) {
- ret = -EFAULT;
- goto err;
- }
+ if (packet->recv_wc)
+ ret = copy_recv_mad(buf, packet, count);
+ else
+ ret = copy_send_mad(buf, packet, count);
- if (count < packet->length + sizeof (struct ib_user_mad))
- /*
- * User buffer too small. Return first RMPP segment (which
- * includes RMPP message length).
- */
- ret = -ENOSPC;
- else if (packet->length <= sizeof(struct ib_mad))
- ret = packet->length + sizeof(struct ib_user_mad);
- else {
- int len = packet->length - sizeof(struct ib_mad);
- struct ib_rmpp_mad *rmpp_mad =
- (struct ib_rmpp_mad *) packet->mad.data;
- int max_seg_payload = sizeof(struct ib_mad) -
- data_offset(rmpp_mad->mad_hdr.mgmt_class);
- int seg_payload;
- /*
- * Multipacket RMPP MAD message. Copy remainder of message.
- * Note that last segment may have a shorter payload.
- */
- buf += sizeof(struct ib_user_mad) + sizeof(struct ib_mad);
- list_for_each_entry(seg, &packet->seg_list, list) {
- seg_payload = min_t(int, len, max_seg_payload);
- if (copy_to_user(buf, seg->data, seg_payload)) {
- ret = -EFAULT;
- goto err;
- }
- buf += seg_payload;
- len -= seg_payload;
- }
- ret = packet->length + sizeof (struct ib_user_mad);
- }
-err:
if (ret < 0) {
/* Requeue packet */
spin_lock_irq(&file->recv_lock);
list_add(&packet->list, &file->recv_list);
spin_unlock_irq(&file->recv_lock);
- } else
- free_packet(packet);
+ } else {
+ if (packet->recv_wc)
+ ib_free_recv_mad(packet->recv_wc);
+ kfree(packet);
+ }
return ret;
}
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